From jira-return-10378-archive-asf-public=cust-asf.ponee.io@kafka.apache.org Fri Mar 2 02:28:05 2018 Return-Path: X-Original-To: archive-asf-public@cust-asf.ponee.io Delivered-To: archive-asf-public@cust-asf.ponee.io Received: from mail.apache.org (hermes.apache.org [140.211.11.3]) by mx-eu-01.ponee.io (Postfix) with SMTP id 718AA180679 for ; Fri, 2 Mar 2018 02:28:04 +0100 (CET) Received: (qmail 20191 invoked by uid 500); 2 Mar 2018 01:28:03 -0000 Mailing-List: contact jira-help@kafka.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: jira@kafka.apache.org Delivered-To: mailing list jira@kafka.apache.org Received: (qmail 19824 invoked by uid 99); 2 Mar 2018 01:28:03 -0000 Received: from pnap-us-west-generic-nat.apache.org (HELO spamd4-us-west.apache.org) (209.188.14.142) by apache.org (qpsmtpd/0.29) with ESMTP; Fri, 02 Mar 2018 01:28:03 +0000 Received: from localhost (localhost [127.0.0.1]) by spamd4-us-west.apache.org (ASF Mail Server at spamd4-us-west.apache.org) with ESMTP id 8D4E3C0611 for ; Fri, 2 Mar 2018 01:28:02 +0000 (UTC) X-Virus-Scanned: Debian amavisd-new at spamd4-us-west.apache.org X-Spam-Flag: NO X-Spam-Score: -110.311 X-Spam-Level: X-Spam-Status: No, score=-110.311 tagged_above=-999 required=6.31 tests=[ENV_AND_HDR_SPF_MATCH=-0.5, RCVD_IN_DNSWL_MED=-2.3, SPF_PASS=-0.001, T_RP_MATCHES_RCVD=-0.01, USER_IN_DEF_SPF_WL=-7.5, USER_IN_WHITELIST=-100] autolearn=disabled Received: from mx1-lw-us.apache.org ([10.40.0.8]) by localhost (spamd4-us-west.apache.org [10.40.0.11]) (amavisd-new, port 10024) with ESMTP id dApDgFvtPTAr for ; Fri, 2 Mar 2018 01:28:01 +0000 (UTC) Received: from mailrelay1-us-west.apache.org (mailrelay1-us-west.apache.org [209.188.14.139]) by mx1-lw-us.apache.org (ASF Mail Server at mx1-lw-us.apache.org) with ESMTP id 8B76A5F3CE for ; Fri, 2 Mar 2018 01:28:01 +0000 (UTC) Received: from jira-lw-us.apache.org (unknown [207.244.88.139]) by mailrelay1-us-west.apache.org (ASF Mail Server at mailrelay1-us-west.apache.org) with ESMTP id DFD30E0250 for ; Fri, 2 Mar 2018 01:28:00 +0000 (UTC) Received: from jira-lw-us.apache.org (localhost [127.0.0.1]) by jira-lw-us.apache.org (ASF Mail Server at jira-lw-us.apache.org) with ESMTP id 463EA2476E for ; Fri, 2 Mar 2018 01:28:00 +0000 (UTC) Date: Fri, 2 Mar 2018 01:28:00 +0000 (UTC) From: "Blake Miller (JIRA)" To: jira@kafka.apache.org Message-ID: In-Reply-To: References: Subject: [jira] [Commented] (KAFKA-4936) Allow dynamic routing of output records MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-JIRA-FingerPrint: 30527f35849b9dde25b450d4833f0394 [ https://issues.apache.org/jira/browse/KAFKA-4936?page=3Dcom.atlassian= .jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=3D1638= 2969#comment-16382969 ]=20 Blake Miller commented on KAFKA-4936: ------------------------------------- That is a very good point about the potential to=C2=A0create=C2=A0oodles of= topics unintentionally. I don't think you're overthinking it... there is s= ignificantly more complexity to it than I recognized at first, and I was no= t considering automatic topic creation. I pondered it a bit more just now, = and came to the tentative conclusion that this feature could be implemented= in a safe and simple way *only* in the absence of automatic topic creation= . I personally do not understand=C2=A0what value automatic topic creation off= ers,=C2=A0it=C2=A0seems to me to abstract over=C2=A0very important details = that the Kafka user should think about (partitioning, at least), and also t= o=C2=A0lower the bar for mistakes or bad code doing damage,=C2=A0in order t= o gain what seems like a very tiny bit of convenience.=C2=A0Perhaps somebod= y who understands the=C2=A0value proposition of automatic topic creation ca= n comment on its relevance to this issue. Regarding the implementation details, I hadn't thought very deeply into it = myself, but what you say makes sense, and even without automatic topic crea= tion, the implementation would have to=C2=A0handle the eventuality of the t= opic not existing. I wonder what happens in the current implementation if I give a nonexistent= output topic to a StreamBuilder and then .start() it, specifically would i= t be a runtime error somewhere in a SinkNode=C2=A0after=C2=A0the=C2=A0Kafka= Streams app is started, or would StreamBuilder.build() complain? I will=C2= =A0give that a try. =C2=A0 =C2=A0 > Allow dynamic routing of output records > --------------------------------------- > > Key: KAFKA-4936 > URL: https://issues.apache.org/jira/browse/KAFKA-4936 > Project: Kafka > Issue Type: Improvement > Components: streams > Reporter: Matthias J. Sax > Priority: Major > Labels: needs-kip > > Currently, all used output topics must be know beforehand, and thus, it's= not possible to send output records to topic in a dynamic fashion. > There have been couple of request for this feature and we should consider= adding it. There are many open questions however, with regard to topic cre= ation and configuration (replication factor, number of partitions) etc. -- This message was sent by Atlassian JIRA (v7.6.3#76005)